According to media reports, scientists captured a long-handled bat near an abandoned Liberia mine, which found one-fifth of the Ebola virus genome.
The Ebola outbreak that hit West Africa between 2013 and 2016 surprised the world. This virus has never been found in the area. All previous Ebola outbreaks broke out in Central Africa or Sudan. This becomes a mystery: Where did the Ebola virus come from?
Now scientists may have an answer. Near an abandoned mine mouth in Liberia, they caught a bat, which is likely to be infected with the Ebola virus. The researchers did not isolate the virus itself but found about one-fifth of the Ebola virus genome in the bat. It is too early to tell if it is exactly the same as the virus that ravages the region. However, Fabian Leendertz, a veterinary epidemiologist at the Robert Koch Institute in Berlin, said: “This is an important new clue and should be widely tracked.”
Jon Epstein, a veterinary epidemiologist at the New York City Eco-Health Alliance, said the findings also provide new clues to the natural history of the Ebola virus. The Ebola virus has plagued scientists for decades. Epstein is one of the members of this discovery. He said: “This is indeed the first evidence that we found any bat carrying Ebola in the area. It gives us a deeper understanding of where the virus comes from.”
Tolbert Nyenswah, director of the National Institute of Public Health of Liberia, announced the results today at a press conference in Monrovia. Columbia University virologist Simon Anthony said the Liberian government and other partners “consider that this is an important finding that deserves public attention regardless of scientific publications.”
This reflects how emotional this topic is. In Liberia, a country of about 4 million people, the virus has more than 10,000 people, nearly half of them die; and 6,500 in Sierra Leone and Guinea. Many people in West Africa are worried that the virus will come back. A press release issued today by the Ministry of Health and Social Welfare of Liberia has been highlighted three times in bold, and there are currently no known cases of human Ebola in the country.
The Ebola viral RNA fragment was found in the mouth of a large long-handled bat. The bat was arrested in 2016 in the Sanniquellie-Mahn district bordering Guinea with Liberia. Bats live in many parts of Africa, inhabit caves and feed on insects. Scientists have previously discovered two other Ebola viruses, M.schreibersii, in a related insectivorous bat.
However, Epstein said that most other evidence points out that fruit bats are carriers of the Ebola virus. “What it really tells me is that this is a virus with multiple hosts, and it may depend on which species carry the virus.”
Leendertz of the Robert Koch Institute agrees that the concept of a single virus-carrying species may be too simple. Vincent Munster, a virus ecologist at the National Institute of Allergy and Infectious Diseases in Hamilton, Mont., says the situation may be similar to bird flu, which is spread by nature in a variety of duck species and wading birds.
Leendertz said the next step might be to sample long-handed bat-preying insects. He said: “One question raised by this discovery is whether the positive samples really point to infected bats or from virus-carrying insects eaten by bats.”
This is a very difficult task. In other parts of Africa, scientists have spent decades searching for the source of the Ebola virus, but so far there has been little success. In a project currently funded by the United States Agency for International Development, Anthony tested more than 11,000 samples from bats, rodents and livestock in West Africa. The results of the survey released today are the only positive tests to date.
Even this time is not very clear, the initial test is contradictory to the existence of the virus. Anthony said, “I once thought that this is not true.” He only extracted about 20% of the entire Ebola virus genome, but these fragments are more similar to the virus that causes West African outbreaks than any other strain. The research team hopes to find more viruses in another sample, which are still in the swabs in the refrigerator.
Munster said the findings suggest that there may be more outbreaks in West Africa. He said that this “should be an urgent appeal to strengthen the general medical infrastructure in the region”, including investment in training medical workers and African scientists. Epstein said the findings should also strengthen public health information to avoid direct contact with bats, avoiding hunting, eating or killing bats. He said: “The good news is that the large long-handed bats carrying the Ebola virus are not common in human settlements.”